<?php

class Ext_Article
{
    protected static $_instance = null;
    
    public static function getInstance()
    {
        $_className = _get_called_class();
        if (!isset(self::$_instance[$_className])) {
            self::$_instance[$_className] = new $_className();
        }

        return self::$_instance[$_className];
    }
    
    protected function __construct()
    {

    }
    
    public function show($articleId)
    {
        return new Ext_Article_Show($articleId);
    }
}
